Magneto.



O. HEINS I C. NI. WILD.

MAGNETO.

APPLICATION FILED MAR. Il ISIS. 1,225,330. l Patented May 8, 1917.

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he; N3 I a I N5 III I u @I I II 0. HEINS 6L C. Wl. WILD.

MAGNETO.

APPLICATION FILED MAR. l. l9l6.

Patented May 8, 1917.

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lUNITED sTATEs PATENT orFIoE.

OTTO HEINS, OF NEW YORK, N. Y., AND CHARLES M. WILD, 0F SPRINGFIELD, MASSA- CHUSETTS, ASSIGNORS TO BOSCH MAGNET() COMPANY, F NEW YORK, N. Y., A GOR- PORATION OF NEW YORK.

MAGNETO.

To all whom t may concern:

Be it known that we, OTTO HEINs and CHARLES M. VV-ILD, both subjects of the Emperor of Germany, residing in the 4city of New York, county and State of New York, and city of Springfield, county of Hampden, and State of Massachusetts, respec- I tively, have invented certain new and useful Improvements in Magetos; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains tomake and use the same.

ing two ignition voltages per rotation is unsatisfactory in electric ignition systems -for high speed 'four-cycle internal combustion engines operating at 2500 to 3500 R. P. M. and having four or six cylinders, and also for vfour-cycle engines loperating at low speed and having many cylinders, such as twelve. This is due to the fact that the centrifugal frce acting on the deflecting interrupter element sometimes causes the magneto to miss, and also the fact that themagneto gearing operates unsatisfactorily at high speed. Magnetos producing four vsparks per rotation have been designed to overcome these disadvantages, but, although this type of magneto may be mounted directly on the 'crank shaft of eight-cylinder engines, magneto gearing is required for six and twelve cylinder engines.

The object of the present invention is to provide' a Jmagneto for high speed engines and particularly a magneto that can be driven directly from the crank shaft of a six or a twelve cylinder four-cycle engine. In the preferred form of construction, we

`vattain this result by a novel combination armature., f By providing a mechanical interrupter with six cams, and suitable distributing mechanism, the magneto may be mounted on the crank shaft of a twelve cylnder four-cycle engine; and by providing Specification of Letters Patent.

The customary bipolar magneto producthree interrupter cams and suitable distributing mechanism, only the alternate ignition voltages that the magneto .is capable of generating are utilized, so that the magneto is appropriate for mounting directly on the crank shaft of a six cylinder four-cycle eneine- In the accompanying drawings illustrating the preferred embodiment of our invention, in application, as an example, to a magneto generating three ignition voltages per rotation, and having distributing mechanism driven at crank shaft speed for a sixcylinder four-cycle engine in order to eliminate the distributer gearing also,

Figure 1 is a central vertical section taken longitudinally of the magneto; Figs. 2,l 3 and 4 are sections on lines 2-2, 3 3 and lL-4, respectively, of Fig. l; Fig. 5 is a front view of the mechanical interrupter with the cover removed; and Fig. 6 is a wiring diagram.

The armature core is of the ordinary shuttle type having a cross barV 1 connecting two polar projections 2, and is mounted for" rotation in the bearings 3. The core is provided with` a primary winding 4 and la sc condary winding 5.

The field member is stationary and is composed of three permanent magnets 6, 7 and 8 of horse-shoe form, arranged side by side along the axis of rotation of the armature,

' as shown. It will be observed that in the magnets 7 and 8 one arm is shorter than the other, the short arm 7 of the magnet 7 be-l ing on the same side of the magneto as the long arm 8 of the magnet 8, while the long arm 7 and the short arm 8 are on the same side. It will also be observed that the two arms 6 and 6 of the magnet 6 are of the s ame length as each other, and of they same length as the long arms of the magnets 7 and 8. The magnet 6 is provided with pole shoes 9 and 9 disposed along the horizontal -diameter of the armature, whereas the pole shoes 10 and 10 of the magnet 7, and the pole shoes 11 and 11 of the magnet 8 are disposed along the respective diameters at to the horizontal, as indicated by the broken lines in Figs. 2, 3 and 4. It will also be observed that the magnets 6 and 7, together with their pole shoes 9, 9 and 10', l0, are wider measured along the axis of rotation of the arme7 Patented May 8, 1917.

Application mea March 1, 191e. serial No. 81,349.

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ture than the magnet 8 and its pole shoes 11 and 11, the result being that substantially equal ignition voltages are generated in each rotation. The adjacent magnet arms 6, 7 and 8l are of one polarity, say north, While the other adjacent magnet arms 6, 7 and 8 are of the other polarity.

The mechanical interrupter for periodically interrupting the circuit of the primary Winding 4 comprises the grounded interrupter element 12 and the insulated element 12', both mounted for rotation with the armature, and the three equally-spaced interrupter cams 13 carried by a normally stationary cam ring 14 provided with a lever 15 for adjusting at will the circumferential position of the cam ring to advance or retard the period of ignition throughout the timing range. One terminal of the primary winding 4 is connected to the insulated interrupter element 12', and the other terminal is grounded on the magneto frame. The coil condenser 16 is mounted fast with the armature and is electrically connected between the insulated interrupter element 12 and the magneto frame.

The two terminals of the secondary Winding 5 are connected respectively to the aX- ially-displa'eed distributer segments 17 and 17', which are embedded in two insulating rings 18 and 18 at 120O apart around the circumference. In order to provide for the required timing range, each of the segments is approximately 65 in extent. The distributer segments 17 and 17 are carried by the armature for rotation therewith and successively engage the three stationary palrs of spring-pressed brushes 19, 19 and 19, which are individually connected to the insulated electrodes of grounded spark plugs,

The magneto shown may be driven directly from the crank shaft of a six-cylinder four-cycle engine. An ignition voltage is generated in the secondary Winding 5 in those periods in which the polar projections 2 of the armature core bridge the spaces between the pole shoes of the magnets 6, 7 or 8, and in which the mechanical interrupter is opened at the time by reason of the engagement between a cam 13 and the deflecting interrupter element 12. Inasmuch as the pole shoes of the three magnets 6, 7 and 8 are disposed on diametrical lines at 60 to each other, each polar projection 2 will, during each half rotation of the armature, first bridge a space between the pole shoes of one magnet, then a space between the pole shoes of the'second magnet at 60 from the first position, then a space between thepole shoes of the third magnet at 120 from the first position, then the other space between the pole shoes of the first magnet at 180 from the first position, and so on. In each position the polar projections of one partJ of the armature bridge the spaces between the pole shoes of a single one of the magnets 6, 7 or 8, while the remaining portions of the polar projections register in part With the pole shoes of the other two magnets. The ignition voltage generated each time results from the simultaneous interruption of the primary circuit at the interrupter contacts and the diversion of the magnetic fluX of one magnet from its prior path through the polar projections 2 and the cross bar 1 of the armature to the path across the polar projections alone, the time rate of change of the magnetic flux interlinking with the primary winding 4 being sufficient to generate a satisfactory ignition voltage in the secondary winding 5. The magnetic flux from the other magnets does not materially affect the ignition voltage generated at that time, because the path through the remaining parts of the polar projections 2 and the cross bar 1 remain substantially unchanged. In order to prevent the passage of magnetic flux from one to another of the magnets, it is preferable, though not essential, to magnetically insulate those parts of the armature core which cooperate with the pole shoes of the separate magnets, as, for instance, by means of the I-shaped brass members 20, and also to magnetically insulate the sets of pole shoes from each other and the magnets from each other by means of the aluminum members 21. The base 22, together With the side plate 23 carrying the interrupter housing and the side plate 24 carrying the distributer housing, are of non-magnetic material, as aluminum.

As a result of the fact that only three interrupter cams are provided at 120 apart, only three of the siX ignition voltages that the magneto is capable of generating in each rotation, are generated, the alternate three being suppressed as a result of the fact that the primary circuit remains short-circuited by the interrupter element at the time that the magnetic flux from the magnets is diverted in its path through the armature core. However, it will be apparent that those ignition voltages would be generated by this magneto if six interrupt-er cams on 60 spacing were provided, together with suitable distributing mechanism', in which case the magneto Could be mounted on the crank shaft of a twelve-cylinder, four-cycle engine to supply the six ignition voltages required per rotation of the engine. Furthermore, it will be apparent that the distributing mechanism shown herein may be variously modified, either by providing a distributer driven at half crank-shaft speed in the ordinary way to produce a spark at each spark plug in turn, or by means off, distributing mechanism having an intermediate and a main distributer which, at each period of ignition, conduct the ignition current to a single one of the spark plugs at a time, such,

K tems, a rotatable bipolar armature with polar projections, and a six-pole field member composed of three permanent magnets having poles embracing different axial parts of the armature, the polar projections of the larmature being designed to bridgev the spaces between the poles of a single one oi the magnets at a time.

2. In a magneto for electric ignition systems, a rotatable bipolar armature with polar projections, and a six-pole field member composed of three-permanent magnets having poles embracing different axial parts of the armature, the polar projections of the armature being designed to bridge the spaces between the poles of a single one of the magnets at intervals of 60.

3. In a magneto for electric ignition systems, a rotatable bipolar armature with polar projections, and a six-pole -field member composed of three permanent magnets having poles embracing different axial parts of thev armature, one axial part of the polar projections being designed to bridge the spaces between the poles of one of the magnets while the other axial parts simultaneously register with the poles of the other magnets.

4. In a magneto for electric ignition sys-k tems, a rotatable armature of shuttle form, and a six-pole field member -composed of three permanent magnets each having poles embracing a different axial part of the armature.

5. In a magneto for electric ignition systems, a rotatable bipolar armature of shuttle form, and a six-pole field member composed of vthree horse-shoe magnets each having pole shoes disposed on a diameter at 60 to the diameters of the pole shoes of the other magnets and embracing 'a different axial part of the armature.

6. In a magneto for electric ignition systems, a rotatable armature, and a six-pole field member composed of three horse-shoe magnets arranged sideby side along the axis of' the armature and having poles embracing different axial parts thereof. I f

y7. In a magneto for electric ignition systems, -a rotatable armature, and a six-pole field member composed of three horse-shoe diametrical disposition of the poles of the` other magnets.-

8. Ina magneto for electric ignition systems, a rotatable armature, and a six-.pole field member composed of three horse-shoe magnets arranged side by side along the axis of the armature, one magnet having poles disposed on the horizontal diameter, and the other magnets having poles disposed on diameters at 60 to the horizontal di ameter.

9. In a magneto for electric ignition systems, a rotatable armature, anda six-pole field member composed of three horse-shoe magnets arranged side by side along the axis of the armature, one magnet'having arms of equal length and poles disposed on the horizontal diameter, and each of the other magnets having a long arm and a short arm so arranged that the poles are disposed on a diameter at 60 to the horizontal diameter.

10. In a magneto Jfor electric ignition systems, a rotatable armature having three axial parts magnetically insulated from each other, and a six-pole field member therefor composed of three permanent magnets having poles embracing the respective parts of the armature.

11. In a magneto for electric ignition systems, a rotatable armature, and a six-pole field member therefor composed of three permanent magnets having poles embracing different axial parts of the armature, the three magnets being magnetically insulated from each other.

12. In a magneto for electric ignition systems, a rotatable armature, and a six-pole field member therefor composed of three permanent magnets arranged side by side along the axis of the armature and having poles embracing different axial parts of the armature, and spacing members of nonmagnetic material arranged between the magnets to magnetically insulate them.

each having poles embracing a dierent.

axial part of the armature core, and a generating winding mounted on the armature core in coperation with the poles of the three magnets. j

15. In a magneto for electric ignition systems, an armature core, a six-pole field member composed of three permanent magnets -1 each having poles embracing a different' axial part of the armaturecore, and a genilo erating winding embracing the armature core in coperation with the poles of the three magnets.

16. The combination with a magneto having a. rotatable armature with primary and secondary windings, and a six-pole field member cooperative with the armature,'of spark plug distributing segments connected to the respective terminals of the secondary winding and carried by the armature at axially separated places.

17. The combination with a magneto having a rotatable armature with primary and secondary windings, and a eld member cooperative with the armature, of distributing mechanism comprising two segments connected to the respective terminals of the secondary winding and carried by the armature at axially separated places, and six stationary spark plug distributing brushes arranged in two circular series cooperative with the segments.

18. The combination with a magneto having a rotatable armature with a winding thereon, and a six-pole field member cooperative with the armature, of a mechanical interrupter having three interrupter cams to alter the circuit of the armature winding at three periods in each rotation.

19. The Vcombination with a magneto having a rotatable armature-with a Winding thereon, and a six-pole field member cooperative with the armature and capable of generating in the winding six ignition voltages per rotation, of a mechanical interrupter having three interrupter cams arranged to alter the circuit of the winding at alternate ones of the six periods at which the ignition voltages may be generated in each rotation.

20. The combination with a magneto having a rotatable armature with a winding thereon, and a six-pole field member cooperative with the armature and capable of generating in the winding six ignition voltages ,per rotation, of a mechanical interrupter having three interrupter cams arranged to alter the circuit of the winding Aat alternate ones of the six periods at which the ignition voltages may be generated in each rotation, and distributing mechanism for distributing the ignition voltages generated in each rotation to spark plugs.

In testimony whereof we affix our signatures.

OTTO HEINS. CHARLES M. WILD. 

